Color Devourer

Colorless Form. The Color Devourer can hold up to three stolen colors at a time. If the devourer is incapacitated or dies, all colors stolen by it immediately return to their owners.

Stolen Colors. A creature that has lost a color suffers the corresponding effect until that color is restored.

• Red. The creature can't regain hit points.
  
• Blue. The creature can't cast spells of 1st level or higher.
• Yellow. The creature can't take reactions.

Void Brush. The devourer's Void Brush can be coated in one stolen color at a time. When the devourer coats the brush in a new color, the previous effect ends.

• Red. The Void Brush deals an extra 7 (2d6) necrotic damage on hit. The devourer regains hit points equal to half the necrotic damage dealt in this way.
  
• Blue. The Void Brush deals an extra 7 (2d6) force damage on hit. A creature hit by the brush has disadvantage on the next Constitution saving throw it makes to maintain concentration before the start of the devourer's next turn.
• Yellow. The Void Brush deals an extra 10 (3d6) lightning damage on hit. In addition, while the brush is coated in yellow pigment, the devourer can use its Yellow Counterstrike reaction.

Multiattack. The Color Devourer makes two Void Brush attacks. It can replace one of the attacks with Devour Color.

Void Brush. Melee Weapon Attack: +9 to hit, reach 10 ft., one target. Hit: 14 (2d8 + 5) slashing damage, plus any extra damage from the brush's current color.

Devour Color. The devourer targets one creature it can see within 60 feet of itself. The target must succeed on a DC 17 Charisma saving throw or lose one color of the devourer's choice: red, blue, or yellow. The devourer can't choose a color the target has already lost.

The devourer holds the stolen color, and the target suffers the corresponding effect described in the Stolen Colors trait.

On a successful save, the target is immune to Devour Color until the end of the target's next turn.

Apply Pigment. The devourer chooses one stolen color it is holding and coats the Void Brush in that color. A Pigment Orb of the chosen color appears in an unoccupied space the devourer can see within 30 feet of itself.

The color remains stolen until the corresponding Pigment Orb is destroyed.

Empty Canvas Burst (Recharge 5-6). The devourer releases a wave of colorless energy in a 30-foot cone. Each creature in that area must make a DC 17 Dexterity saving throw, taking 31 (7d8) force damage on a failed save, or half as much damage on a successful one.

A creature that fails the save can't have advantage on attack rolls or ability checks until the start of the devourer's next turn.

Smear. When the devourer is hit by an attack, it adds 3 to its AC against that attack, potentially causing the attack to miss.

Yellow Counterstrike. When a creature within 10 feet of the devourer hits it with an attack while the Void Brush is coated in yellow pigment, the devourer can make one Void Brush attack against that creature.

The Color Devourer can take 3 legendary actions, choosing from the options below. Only one legendary action option can be used at a time and only at the end of another creature's turn. The devourer regains spent legendary actions at the start of its turn.

Move. The devourer moves up to half its speed without provoking opportunity attacks.

Brush. The devourer makes one Void Brush attack.

Pigment Burst (Costs 2 Actions). The devourer chooses one Pigment Orb it can see within 60 feet of itself. Each creature within 10 feet of the orb must make a DC 17 Dexterity saving throw, taking 13 (3d8) damage on a failed save, or half as much on a successful one. The damage type depends on the orb's color: necrotic for red, force for blue, or lightning for yellow.

Devour Color (Costs 3 Actions). The devourer uses Devour Color.

Devour All Colors (Once per encounter)
When the Color Devourer is first reduced to half its hit points or fewer, it drains the remaining colors from the battlefield.

Each creature of the devourer's choice within 60 feet of it must make a DC 17 Charisma saving throw. On a failed save, the creature loses its red, blue, and yellow colors until the end of the devourer's next turn. A creature that has already lost one or more of these colors loses only the remaining colors.

While a creature is deprived of all three colors in this way:

• it can't regain hit points;
• it can't cast spells of 1st level or higher;
• it can't take reactions.

For each creature that fails the saving throw, one Pigment Orb appears in an unoccupied space the devourer can see within 30 feet of that creature. The orb contains all colors stolen from that creature.

When that Pigment Orb is destroyed, all colors contained within it immediately return to their owner.

After using this ability, the devourer can't use Devour Color until the end of its next turn.